The embodiment relates to a light emitting device, a method of manufacturing the same, and a light emitting device package.
A light emitting device (LED) includes a p-n junction diode having a characteristic of converting electric energy into light energy. The p-n junction diode can be formed by combining group III and V elements of the periodic table. The LED can represent various colors by adjusting the compositional ratio of compound semiconductors.
When forward voltage is applied to the LED, electrons of an n layer are bonded with holes of a p layer, so that energy corresponding to an energy gap between a conduction band and a valance band may be generated. This energy is mainly realized as heat or light, and the LED emits the energy as the light.
A nitride semiconductor represents superior thermal stability and wide bandgap energy, so the nitride semiconductor has been spotlighted in the field of optical devices and high-power electronic devices. In particular, blue, green, and UV light emitting devices employing the nitride semiconductor have already been developed and extensively used.
Meanwhile, in order to realize a white LED package, LEDs of red, green and blue colors, which are three primary colors of light, are combined with each other, the yellow phosphor (YAG or TAG) is added to the blue LED, or red/green/blue phosphors are employed in the UV LED.
However, in the white LED package using the phosphor according to the related art, the phosphor may not be uniformly distributed around an LED chip, resulting in the wide color temperature distribution.
In addition, according to the related art, the distribution area of the phosphor is relatively larger than the area of the LED, so that the phosphor may not be uniformly distributed around the LED, resulting in the wide color temperature distribution.
In addition, according to the related art, the light converted by the phosphor is total-reflected from a boundary surface of the background material and then introduced again into the LED chip, so that the efficiency of the white LED may be degraded.